After a diagnosis of stomach cancer, you will likely have imaging tests. These tests help your health care providers learn more about your cancer. They can help show the type of cancer you have, and its specific location. They also help show the stage of the cancer. The stage of a cancer is how much it has spread. The test results help your health care providers decide the best ways to treat the cancer. The imaging tests you will have may include:
Endoscopic ultrasound (EUS)
Laparoscopic ultrasound (LUS)
Positron-emission tomography (PET) scan
A CT scan is a series of X-rays that are put together by a computer. You may have CT scans of your chest, abdomen, and pelvis. These are to check for signs of cancer in other organs like your liver or lungs. The test may look at nearby lymph nodes or glands. Lymph nodes are common places for stomach and other cancers to spread.
A CT scan is painless. It is not invasive. You may be asked to hold your breath 1 or more times during the scan. You may be asked to drink a contrast dye 4 to 6 hours before the scan. The dye helps to show certain tissues and organs better on the images.
During the test, you lie still on an exam table. The table slides through the center of the CT scanner. The scanner directs a beam of X-rays at a certain part of your body. A computer uses the data from the X-rays to make a series of pictures. The pictures are put together to create a 3-dimensional picture.
An ultrasound uses sound waves and a computer to make images. An endoscopic ultrasound is done from inside the stomach. It uses a tool called an endoscope. An endoscope is a thin, flexible tube with a light and a tiny camera. The scope has a special ultrasound tool at the tip. This test shows how far cancer has spread into the wall of your stomach and nearby tissues and lymph nodes. It is more accurate than a CT scan. It gives very specific information about the stage of your stomach cancer. This information helps your health care providers plan your treatment.
Before the test, your throat is sprayed with anesthetic. This numbs your throat and helps prevent gagging. You may also receive medicine to help you relax. The endoscope is put into your mouth or nose. It is gently guided down into your throat, your esophagus, and then your stomach. It sends images to a computer.
EUS can show how far the tumor has grown in or through the walls of your stomach. EUS can also look at lymph nodes around your stomach to see if cancer cells have spread to them. Your health care provider may pass a thin needle from the endoscope through your stomach wall and into nearby lymph nodes. Then he or she can take tiny pieces tissue from the lymph nodes. This is called a biopsy. The tiny pieces of tissue are sent it to a pathologist to see if they have cancer cells.
Laparoscopic ultrasound also uses sound waves to make pictures. This test is best at finding cancer that has spread to other organs and tissue, such as the liver and lymph nodes. It can find small growths that are not easily seen on CT scans. It may be done before surgery to find all of the cancer.
For this test, a surgeon makes small cuts, or incisions, in your abdomen. A flexible tool called a laparoscope is put through 1 incision. The scope has an ultrasound probe. The sound waves given off by the ultrasound probe help to find any cancer in nearby areas. The surgeon may also take a biopsy to be tested.
An MRI scanner uses large magnets and a computer to make images. This creates very clear images. An MRI is used to see if cancer has spread outside of your stomach. For example, it can spread to lymph nodes, or to the liver or pancreas.
For this test, you lie still on a table as it passes through a tube-like scanner. The scanner sends a radiofrequency waves at the area of your body to be viewed. A computer puts together the data to create a 3-dimensional image of the inside of your body.
When the scanner is working, it is very loud. You may be given earplugs or headphones to wear. The scanner is a small space. If you are uncomfortable in small spaces, you may be given a sedative. Take this before this test. Some hospitals and clinics have open MRI scanners. These are less confining. A 2-way intercom will let you talk to technician during the test.
This test finds any cancer cells that may be growing in your bones.
For this test, a very small amount of a radioactive substance is injected into one of your veins. It travels through the bloodstream. It then collects in areas of bone where there is abnormal growth. You lie on a table for about 30 minutes while a machine scans your body. The machine looks for any areas where the substance has collected. If abnormal areas are found, you may also have an MRI or a CT scan.
This test helps show whether cancer has spread beyond the stomach. During the test, a sugar (glucose) solution is injected into one of your veins. Cancer cells use the glucose more quickly than normal cells do. A scanner makes images that show where the glucose has collected. This shows areas that may be cancer.